2-232540387-C-T

Position:

chr2-232540387-C-T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_005199.5(CHRNG):c.202C>T(p.Arg68Ter) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000285 in 1,614,048 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000029 ( 0 hom. )

Consequence

CHRNG
NM_005199.5 stop_gained

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:5

Conservation

PhyloP100: 1.19

Variant links:

Genes affected

CHRNG (HGNC:1967): (cholinergic receptor nicotinic gamma subunit) The mammalian muscle-type acetylcholine receptor is a transmembrane pentameric glycoprotein with two alpha subunits, one beta, one delta, and one epsilon (in adult skeletal muscle) or gamma (in fetal and denervated muscle) subunit. This gene, which encodes the gamma subunit, is expressed prior to the thirty-third week of gestation in humans. The gamma subunit of the acetylcholine receptor plays a role in neuromuscular organogenesis and ligand binding and disruption of gamma subunit expression prevents the correct localization of the receptor in cell membranes. Mutations in this gene cause Escobar syndrome and a lethal form of multiple pterygium syndrome. Muscle-type acetylcholine receptor is the major antigen in the autoimmune disease myasthenia gravis.[provided by RefSeq, Sep 2009]

CHRNG links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 ACMG points.

PVS1

Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 2-232540387-C-T is Pathogenic according to our data. Variant chr2-232540387-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 548021.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-232540387-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CHRNG	NM_005199.5 linkuse as main transcript	c.202C>T	p.Arg68Ter	stop_gained	3/12	ENST00000651502.1	NP_005190.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CHRNG	ENST00000651502.1 linkuse as main transcript	c.202C>T	p.Arg68Ter	stop_gained	3/12		NM_005199.5	ENSP00000498757	P1	P07510-1
CHRNG	ENST00000389492.3 linkuse as main transcript	c.202C>T	p.Arg68Ter	stop_gained	3/11	1		ENSP00000374143		P07510-2
CHRNG	ENST00000485094.1 linkuse as main transcript	n.223C>T		non_coding_transcript_exon_variant	3/5	1

Frequencies

GnomAD3 genomes

AF:

0.0000263

AC:

AN:

152100

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000242

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000193

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000199

AC:

AN:

251408

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135892

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000352

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000287

AC:

AN:

1461830

Hom.:

Cov.:

AF XY:

0.0000220

AC XY:

AN XY:

727228

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000252

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000333

Gnomad4 OTH exome

AF:

0.0000331

GnomAD4 genome

AF:

0.0000263

AC:

AN:

152218

Hom.:

Cov.:

AF XY:

0.0000403

AC XY:

AN XY:

74430

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000194

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000557

Hom.:

Bravo

AF:

0.0000189

ExAC

AF:

0.0000247

AC:

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Autosomal recessive multiple pterygium syndrome

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center

Apr 04, 2024

- -

Scoliosis;C1837407:Ankle flexion contracture;C4025173:Arthrogryposis-like hand anomaly

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Center for Reproductive Medicine, Peking University Third Hospital

Oct 16, 2019

- -

Lethal multiple pterygium syndrome

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Breakthrough Genomics, Breakthrough Genomics

Dec 31, 2019

This variant has not been previously reported in the literature. However, other truncating variants such as: W139X, R448X, Q18X and R46X have been detected in families with Escobar syndrome/ multiple pterygium syndrome [PMID: 16826520, 16826531]. -

Autosomal recessive multiple pterygium syndrome;C1854678:Lethal multiple pterygium syndrome

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Mayo Clinic Laboratories, Mayo Clinic

Jan 12, 2018

- -

not provided

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 18, 2024

This sequence change creates a premature translational stop signal (p.Arg68*) in the CHRNG gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in CHRNG are known to be pathogenic (PMID: 16826520). This variant is present in population databases (rs764266722, gnomAD 0.004%). This premature translational stop signal has been observed in individual(s) with multiple pteygium syndrome (PMID: 22167768). ClinVar contains an entry for this variant (Variation ID: 548021). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.55

BayesDel_noAF

Pathogenic

0.44

CADD

Pathogenic

DANN

Uncertain

1.0

Eigen

Uncertain

0.55

Eigen_PC

Uncertain

0.35

FATHMM_MKL

Uncertain

0.86

MutationTaster

Benign

1.0

A;A;A

Vest4

0.87

GERP RS

3.0

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.060

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over